Newest 'ffmpeg' Questions - Stack Overflow

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• Is available standalone ffmpeg as application

  4 novembre 2012, par YShinkarev

  Is available this application? I do not want compile ffmpeg and add it to android project. I want execute application over sh.

• FFMPEG Video to still images and back to video loss less

  4 novembre 2012, par Rigoni

  I'm trying to extract image from an uncompressed AVI video using ffmpeg with the command:

      ffmpeg -i sorce.avi -f image2 -pix_fmt bgr24 images/%1d.bmp
  

  All is ok, but now I need to revert these images back to a video file. I'm trying using this command:

      ffmpeg -f image2 -r 24 -i marked/%1d.bmp -y -vcodec ffv1 -pix_fmt bgr24 test.avi
  

  But, the output video is compressed and with bad quality.

  Is there any way to extract the images in RGB format and than back to a lossless video?

  I also tryed to use -vcodec rawvideo, but the quality still bad.

  Best regards.

• Stream wmv files from unix server

  4 novembre 2012, par Ascii Dude

  I want to stream videos to tvu player and I have a Linux server so I can't use windows media server. For TVU I need to stream them as wmv files. I've done some research and it seems that vlc server and ffmpeg server could work, but I can't seem to find any definitive answer

  With either of these servers can I: - make a playlist of wmv files and just stream it in a loop (go back to the beginning of the playlist after the last file plays) OR - transcode mp4 files on the fly and then play them in a playlist? i can convert them all individually but if it doesn't take too much cpu overhead it would be easier to transcode them on the fly.

• accurate cutting of video (+ audio) with ffmpeg [migrated]

  4 novembre 2012, par Pete Oakey

  I want my website to allow users to accurately create their own clips from a source video I provide.

  I have a source video file that I first want to convert to something suitable for a website:

  Input #0, matroska,webm, from 'source.mkv': 
  Duration: 00:28:18.57, start: 0.000000, bitrate: 10183 kb/s 
  Stream #0:0: Video: h264 (Constrained Baseline), yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], 23.98 fps, 23.98 tbr, 1k tbn, 48 tbc (default)
  Stream #0:1: Audio: mp3, 44100 Hz, stereo, s16, 128 kb/s (default)
  

  So I use ffmpeg to convert it like so:

  ffmpeg -i source.mkv -c:v libx264 -c:a aac -strict experimental -vf scale="960:-1" source.mp4
  

  Watching this video back it is good enough quality and small enough file size for my needs, and loads/plays on my website.

  So I have a webpage that lets users select a start and endpoint on this video - and create a clip. Here's an example of the ffmpeg command that I use for that:

  -ss 577.920 -i source.mp4 -t 011.980 -codec:v copy -codec:a copy -vf scale="960:-1" clip1.mp4
  

  The problem is the clip is not always time-accurate enough. Usually the audio is accurate enough but the video stops half a second early or something.

  Is there any way to make this accurate and in-sync to say, 0.2 of a second?

  EDIT: Adding -force_key_frames 00:00:00.2 didn't help.

• RTP Streaming with the FFmpeg Library

  3 novembre 2012, par volting

  Is ffmpeg's muxing.c example a suitable starting point for developing an RTP based video streamer ?

  ---

  I have a requirement to stream raw image frames from an in memory buffer over the network.

  I've decided on ffmpeg for this task and have managed so far to encode the raw frames into mpeg2 packets. Now I'm working on writing the code to stream the compressed frames, using ffmpegs muxing.c example as a starting point.

  I've made some small changes to begin with,

  avformat_network_init();
  filename = "rtp://192.168.1.141:39000";
  
  /* allocate the output media context */
   avformat_alloc_output_context2(&oc, NULL, "rtp", filename);
  

  After adding the above I get the following output, which says that only one stream is supported in the RTP Muxer.

  

  So I removed the audio stream, then I get no errors, but no output either, although it runs through the main loop without any errors -output below.

  

  Note: I've confirmed that nothing is been sent with wireshark. Also Iv looked at ffserver's source, but it doesn't help that it uses alot of ffmpegs internal headers... which I don't think I should have to do.